First known English use 1663: Archelogia philosophica nova; or, New principles of Philosophy. Containing Philosophy in general, Metaphysicks or Ontology, Dynamilogy or a Discourse of Power, Religio Philosophi or Natural Theology, Physicks or Natural philosophy, by Gideon Harvey (1636/7-1702), London, Thomson, 1663.

Popularized as a philosophical term by German philosopher Christian Wolff (1679–1754).

[Martin] Heidegger's concern […] was with ontology, the nature of beings, above all humans. The central question for him was "What is being? What is it for something to be?" He tackled this question not by way of the sciences, but by way of an examination of our prescientific daily life. We are, he argued, not cut off from the world by our mental processes: we are "in the world", in direct contact with our surroundings.

In the field of philosophy there is some variation in how the term ontology is used. Ontology is a much more recent term than metaphysics and takes its root meaning explicitly from the Greek term for being.Ontology can be used loosely as a rough equivalent to metaphysics or more precisely to denote that subset of the domain of metaphysics which is focused rigorously on the study of being as being.